[CP Staging][No QA] Revert "Prevent LHN from remounting after navigating away from Inbox"

src/libs/Navigation/AppNavigator/createRootStackNavigator/useCustomRootStackNavigatorState/index.ts

@@ -2,11 +2,17 @@ import {isFullScreenName} from '@libs/Navigation/helpers/isNavigatorName';
 import type {CustomStateHookProps} from '@libs/Navigation/PlatformStackNavigation/types';
 
 // This is an optimization to keep mounted only last few screens in the stack.
-// We keep the last full screen and the one before it to avoid unmounting persistent screens
-// (like ReportsSplitNavigator) which contain heavy component trees (e.g. LHN with thousands of items).
 export default function useCustomRootStackNavigatorState({state}: CustomStateHookProps) {
     const lastSplitIndex = state.routes.findLastIndex((route) => isFullScreenName(route.name));
-    const indexToSlice = Math.max(0, lastSplitIndex - 1);
+    let indexToSlice = Math.max(0, lastSplitIndex);
+    const hasPrevRoute = lastSplitIndex > 0;
+    const isPrevFullScreen = isFullScreenName(state.routes.at(lastSplitIndex - 1)?.name);
+
+    // If the route before the last full screen is e.g. RHP, we should leave it in the rendered routes,
+    // as there may be display issues (blank screen) when navigating back and recreating that route to render.
+    if (hasPrevRoute && !isPrevFullScreen) {
+        indexToSlice = lastSplitIndex - 1;
+    }
     const routesToRender = state.routes.slice(indexToSlice, state.routes.length);
     return {...state, routes: routesToRender, index: routesToRender.length - 1};
 }

src/libs/Navigation/AppNavigator/usePreloadFullScreenNavigators.ts

@@ -134,7 +134,6 @@ function usePreloadFullScreenNavigators() {
             }
             hasPreloadedRef.current = true;
             setTimeout(() => {
-                const currentRoutes = navigation.getState().routes;
                 for (const tabName of TABS_TO_PRELOAD) {
                     // Don't preload the current tab
                     const isCurrentTab = TAB_TO_FULLSCREEN[tabName].includes(route.name as FullScreenName);
@@ -148,13 +147,6 @@ function usePreloadFullScreenNavigators() {
                         continue;
                     }
 
-                    // Don't preload tabs whose navigator is already in the regular routes stack
-                    const isRouteInStack = currentRoutes.some((r) => TAB_TO_FULLSCREEN[tabName].includes(r.name as FullScreenName));
-
-                    if (isRouteInStack) {
-                        continue;
-                    }
-
                     // Preload everything else
                     preloadTab(tabName, navigation, subscriptionPlan);
                 }